Idiopathic Premature Ventricular Contractions Exhibiting Preferential Conduction within the Aortic Root

Abstract

A 65-year-old man with frequent premature ventricular contractions (PVCs) underwent electrophysiological testing. Although an excellent pace map was obtained from the right coronary cusp (RCC), radiofrequency ablation at that site interrupted the PVCs transiently. Successful ablation was achieved in the left coronary cusp with earlier local ventricular activation during the PVCs than that in the RCC. These findings suggest that preferential conduction within the aortic root may exist and cause ventricular arrhythmias (VAs) arising from this region to exhibit variable electrocardiographic features, thereby limiting the reliability of electrocardiographic algorithms and pace mapping to predict the site of the VA origin.

Preferential conduction during focal atrial tachycardia arising from the noncoronary cusp

“…Several reports have suggested the existence of preferential conduction during premature ventricular contractions arising from the aortic mitral continuity and aortic sinuses 1, 2, 8, 9. Our case demonstrates that preferential conduction may also occur during AT arising from the aortic sinus.…”

“…Ventricular arrhythmias arising from a single focus within the left ventricular outflow tract and aortic sinuses of Valsalva may exhibit different QRS morphologies owing to preferential conduction to multiple exits 1, 2. We describe a case of an atrial tachycardia (AT) arising from the noncoronary aortic cusp (NCC) with different P-wave morphologies, presumably on the basis of preferential conduction.…”

How to Recognize Epicardial Origin of Ventricular Tachycardias?

“…2 ) [13, 23]. The presence of preferential conduction within the aortic root has been proposed to explain the variability in the electrocardiographic features of aortic cusp arrhythmias and the limited reliability of electrocardiographic algorithms to determine the site of origin [24]. Baman et al report that an R wave in V1 broader than 75 ms can help to differentiate idiopathic epicardial VTs from the coronary venous system [13].…”

Preferential conduction in arrhythmia ablation

“…Therefore, two or more different QRS morphologies featuring multiple breakout sites with only one site of origin can be seen. Ablation from the breakout sites may transiently suppress the arrhythmia and/or cause different QRS morphologies with continuation of the arrhythmia …”

“…Ablation from the breakout sites may transiently suppress the arrhythmia and/or cause different QRS morphologies with continuation of the arrhythmia. [2][3][4][5] In conclusion, preferential conduction should be kept in mind during ablation; therefore, only pace map using either conventionally or software-based algorithms for targeting the arrhythmia, especially in the LVOT, may cause ablation failure.…”